Storage arrays built from a group of drives in a rack have been designed to provide fresh air for the drives, thereby ensuring reliable operation and maximum performance for the drives. FIG. 1 illustrates such a storage array in a rack 100, having a plurality of drives 102 at the front of the rack, and a plurality of fans 104 at the rear of the rack. Airflow 106 cools the drives during use. Note, however, that in such an arrangement, a significant portion of the center of the rack is unused.
Additional designs for storage arrays have aimed to utilize more of the rack depth. As shown in FIG. 2, the rack 100 is filled with four rows of disk drives 102, and a row of fans 104 to cool the drives 102. As a result of such a rack layout, disks toward the rear of the rack reside in a higher temperature environment (i.e., the higher temperature drives 110) than the drives at the front of the rack (i.e., the lower temperature drives 108), because the drives towards the front of the rack 108 preheat the air. As such, higher airflow fans are needed to move the air. Additionally, the added rows of drives add airflow resistance, and thus the fans with higher static pressure abilities are needed. Despite the fans for cooling, the drives towards the rear of the rack will necessarily run hotter, and have higher failure rates.